快速凝固Cu—Cr合金时效析出的共格强化效应

COHERENT STRENGTHENING OF AGING PRECIPITATION IN RAPIDLY SOLIDIFIED Cu-Cr ALLOY

采用单辊快速凝固的方法制备Cu—Cr合金微晶薄带．经适当的时效处理，可以在导电率不降低的前提下．显著提高合金的强度和硬度．强度和硬度的提高主要是由晶粒细化和共格弥散析出强化所造成．共格硬化效果与采用Gerold公式计算的结果非常接近．与常规固溶处理的Cu—Cr合金相比，峰值硬度提高了1．6倍．其中27％由细晶强化产生，73％则由时效析出的并格强化提供．固溶强化和空位强化对快速凝固Cu—Cr合金强度和硬度影响不大。

A single-roller melt spinning method was used to produce Cu-Cr microcrystalline alloyribbons. After proper aging treatment, the strength and hardness of the alloy were remarkably enhancedwhile the conductivity only had a minimal decreajse. The grain refinement and the coherent dispersionstrengthening were proved to be the major factors contributing to the improvement of strength and hardnessof the alloy after aging. The degree of cohereal strengthening is almost idelltical with that calculated byGerold equation. Compared with the solid solution quenched Cu-Cr alloy, the peak hardness is increasedby 160%, in which about 27% results from the grain refinement and 73% from coherent strengthening dueto aging precipitation. Neither the solid solution strengthening nor vacancy strengthening has detectableeffect on the strength and hardness of the rapidly solidified Cu-Cr alloy.